[PATCH 4/4] powerpc/eeh: Avoid event on passed PE

[Alexander Graf]

On 20.05.14 10:30, Gavin Shan wrote:
> If we detects frozen state on PE that has been passed to guest, we
> needn't handle it. Instead, we rely on the guest to detect and recover
> it. The patch avoid EEH event on the frozen passed PE so that the guest
> can have chance to handle that.
>
> Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>

How does the guest learn about this failure? We'd need to inject an 
error into it, no?

I think what you want is an irqfd that the in-kernel eeh code notifies 
when it sees a failure. When such an fd exists, the kernel skips its own 
error handling.


Alex

> ---
>   arch/powerpc/kernel/eeh.c                 | 8 ++++++++
>   arch/powerpc/platforms/powernv/eeh-ioda.c | 3 ++-
>   2 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
> index 9c6b899..6543f05 100644
> --- a/arch/powerpc/kernel/eeh.c
> +++ b/arch/powerpc/kernel/eeh.c
> @@ -400,6 +400,14 @@ int eeh_dev_check_failure(struct eeh_dev *edev)
>   	if (ret > 0)
>   		return ret;
>   
> +	/*
> +	 * If the PE has been passed to guest, we won't check the
> +	 * state. Instead, let the guest handle it if the PE has
> +	 * been frozen.
> +	 */
> +	if (eeh_pe_passed(pe))
> +		return 0;
> +
>   	/* If we already have a pending isolation event for this
>   	 * slot, we know it's bad already, we don't need to check.
>   	 * Do this checking under a lock; as multiple PCI devices
> diff --git a/arch/powerpc/platforms/powernv/eeh-ioda.c b/arch/powerpc/platforms/powernv/eeh-ioda.c
> index 1b5982f..03a3ed2 100644
> --- a/arch/powerpc/platforms/powernv/eeh-ioda.c
> +++ b/arch/powerpc/platforms/powernv/eeh-ioda.c
> @@ -890,7 +890,8 @@ static int ioda_eeh_next_error(struct eeh_pe **pe)
>   				opal_pci_eeh_freeze_clear(phb->opal_id, frozen_pe_no,
>   					OPAL_EEH_ACTION_CLEAR_FREEZE_ALL);
>   				ret = EEH_NEXT_ERR_NONE;
> -			} else if ((*pe)->state & EEH_PE_ISOLATED) {
> +			} else if ((*pe)->state & EEH_PE_ISOLATED ||
> +				   eeh_pe_passed(*pe)) {
>   				ret = EEH_NEXT_ERR_NONE;
>   			} else {
>   				pr_err("EEH: Frozen PHB#%x-PE#%x (%s) detected\n",